I think o1 is best at algorithm heavy coding tasks, opus at api/language-translation knowledge-breath heavy tasks (and also has better recency via later knowledge cutoff). But with latest update opus is pretty close at algorithm heavy coding.
We have plans to put o1 on the leaderboard - but Opus is there RN! We should have a new ELO ranking soon, but the second o1 ranking are done it will be on our leaderboard.